This invention concerns frequency synthesis.
It finds general application in electronics and more particularly in space electronics.
In order to effect frequency synthesis over a wide frequency range with a large number of frequency increments, conventional frequency synthesis techniques, particularly those based on the programmable divider, have three disadvantages:
inadequate spectral purity (signal/noise ratio) at the desired output frequency; PA1 presence of non-harmonic stray radiation; and PA1 high power consumption, which is particularly inconvenient for space applications. PA1 a frequency-modulated oscillator having an input and an output; PA1 a phase comparator having a first input, a second input receiving a reference frequency and an output connected to the input of the oscillator; PA1 a frequency generator having an input receiving the reference frequency of value FO and N outputs, with N being a whole number between 1 and N, each output of the frequency generator being designed to deliver a frequency having a value equal to 2.sup.N FO; and PA1 a phase-locked loop consisting of N links connected in series between the output of the oscillator and the first input of the comparator, each link comprising a mixer having a first input connected to one of the outputs of the frequency generator, a second input and an output, the second input of the current mixer being connected to the output of the preceding mixer or to the output of the oscillator. PA1 an additional frequency-modulated oscillator having an input and an output; PA1 an additional phase-locked loop containing an additional mixer having a first input receiving a predetermined frequency originating from the frequency generator, a second input connected to the output of the additional oscillator and an output, a programmable divider having an input connected to the output of the additional mixer, and an output; and PA1 an additional phase comparator having a first input connected to the output of the programmable divider, a second input receiving an additional reference frequency and an output connected to the input of the additional oscillator. PA1 a frequency-modulated oscillator having an input and an output; PA1 a summing phase-locked loop containing a summing mixer having a first input connected to the output of the oscillator, a second input connected to the output of the summing oscillator; and PA1 a summing phase comparator having a first input connected to the output of the summing mixer, a second input connected to the output of the additional oscillator and an output connected to the input of the summing oscillator.